The above map is based on the OS 1884 edition covering the lower valley of Chediston Blyth Beck and the main channel of the Blyth running through Cookley. The map has been modified to show the position of the stones in Chediston and Cookley (red dots linked by a red line). The area in yellow is land above 100ft. The purple dashed line is the parish boundary between Chediston and Cookley.

Diagram from a section of the estate plan of Chediston Hall (1995): courtesy of Mr James Aldous of Chediston Hall.
It can be seen that the position of the remains of Cedd's Stone is actually in the parish of Wissett. This has been the situation since the first maps were made of this area. Ths position of the parish boundary at this point departs from the ridgeway and takes in a field to the south of the track. A few hundred metres further along to the west, the boundary turns back across the ridgeway to enclose a finger of land projecting into Wissett. It is not known when the parish boundary was established but it is commonly found that parish boundaries seldom follow straight lines. The zig-zags reflect negotionations over the allocation and/or purchase of land when commons, usually situated on community boundaries, were enclosed. The significant point is that Cedd's Stone is virtually on the watershed between two branches of the Blyth running through Wissett and Chediston; an obvious topographical feature separating the two communities in early times.